KUALA LUMPUR, June 22 — A coffee shop operator in Taiwan has put up a banner barring customers aged above 18 years old from addressing her as "auntie”.

The banner came to light after it was shared on social media by a customer on a Facebook group Baofei Commune.

According to social media user, Fuyun Chen, he had patronised the shop located at Taoyuan City and ordered a thick slice of smoked chicken with onion and a glass of cold milk with a server, which Chen addressed as "auntie”.

However, Chen's order was ignored and a customer seated next to him then pointed to the banner hung at the shop's entrance, Taiwan News reported.

In the sign, which included a photo of the operator, said to maintain the quality of food orders, customers who are 18 years and over are not allowed to address the operator as "auntie”.

The operator apparently does not appreciate customers assuming that she was a generation older than them.

Chen said after reading the sign, he immediately rephrased his request by addressing the operator as "beautiful lady boss”.

He claimed that the owner turned around and looked at him before saying the banner was specially made for customers like him.

Before ending his post, Chen expressed hope that he would not find anything weird in his breakfast.

Social media users commented that women should all be called "Older Sister” while men should all be called "Big Brother”.

"If you call all of them beautiful women you won't have any problems.” Others pointed out that it is simply too hard to guess people's age, and it is better just to call men "Mister” and women "Miss”.